% arara: lualatex
\documentclass[a4paper]{article}
%\usepackage{times} % nein...
\usepackage{fontspec}
\setmainfont[Extension=.ttf, %Language=German,
BoldFont=timesbd, ItalicFont=timesi]{times} % ja...
\newfontfamily{\myfont}[Scale=1]{iskpota.ttf}
% U+0D80 (3456) .... U+0DFF (3583) <---- Sinhala!
\newcommand\sinha[2][]{{#1\myfont\symbol{#2}}}
\usepackage{pgffor, mwe}
\begin{document}
\section{Times Test}
\lipsum[66]
\section{Sinhala Test}
Test: {\myfont\symbol{3461}}
Test: \sinha{3461}
\subsection{Unicodebereich}